Gas generator



Spt. 4, 1928. 1,683,155

c. w. BOTSFORD GAS GENERATOR Filed Dec. 26, 1919 2 Sheets-Sheet 1 A 6 Inl/eni'or L K mi'nesses I F i .1 M W W 0M.J

Sept. 4, 1928.

1,683,155 c. w. BOTSFORD GAS GENERATOR Filed Dec. 26, 19

2 sheets-Sheet 2 filvenfor Patented Sept. 4, 1928.

UNITED STATES PATENT OFFICE.

CLAUDE WINFIELD IBOTSFORD, OF CHICAGO, ILLINOIS, ASSIGNOB TO WILLIAM W.ODELL, OF PITTSBURGH, PENNSYLVANIA.

GAS GENERATOR.

Application filed December 26, 1919. Serial No. 347,566.

My invention relates to improvements in gas generators in which I havedeveloped a generator that can be used for manufacturin either watergas, producer gas, carburette water gas, carburetted producer gas orcombinations of an of these using either coke, anthracite coahbituminouscoal or other carbonaceous fuel.

Heretofore there has been considerable difficulty in using bituminous orcoking coal as generator fuel in the manufacture of water gas. Whereattempts have been made to use it, the results were; (1) reducedcapacity; (2) increased consumption of steam per M cubic feet; (3) adecrease in the volume of incandescent fuel in the generator due to thegreater difficulty of heating coal, the temperature of which tends toremain below 250 degrees F. till the moisture is driven off; (4) theproduction of large volumes of smoke during blasting; and (5) theproduction of an excess amount of combustible constituents in the blastgas (more than is required for heating carburetting checker chambers)due to the volatile matter from the coal and the superficial heating ofthe coking coal.

The objects of my invention in detail are:

(1) To produce a combination generator in which water gas can bemanufactured successfully from bituminous fuels without the difficultiesmet with in common practice with the present forms of apparatus.

(2) In which anthracite coal or coke can be used equally as well asbituminous fuel.

(3) In which a greater volume of incandescent fuel is produced from agiven amount of air blast than in the present ractice.

(4) In which the capacity 0 a given sized set is increased with eitherof the fuels mentioned.

(5) In which less CO (carbon dioxide) is produced during a steam run.

(6) In which clinker difiiculties are mitigated or eliminated.

(7) In which less steam is required per 1,000 cu. ft. of water gas made.

(8) In which the loss of fuel in the ash is articularly decreased whenusing bituminous uel, and is reduced to a minimum with any solid fuel.

(9) In which producer gas can be made by a continuous or intermittentprocess.

(10) In which carburetted water gas or car buretted producer gas can bemade.

(11) In which a hot air blast can be safely and advantageously used.

(12 In which the blast air is automatically hea in a chamber within thegenerator.

Fig. 1 is a vertical elevation partially broken away to show in sectionthe interior of the generator;

Fig. 2 is a top view of the generator with the pipe connections thereto;and

Fi 3 is a section taken substantially on the line Y of Fig. 1.

In the drawings there is shown a enerator and connections, in which partof s ell A is eliminated to show the interior in section. B is the bricklining within which the fuel is retained. The air blast connections areshown at D and Q, the valve F controlling the air through Q. G, H and Eare the steam ports and I and V are the steam control Valves. Thecharging door is at J, the cleaning door at K and the ash pit door at L,while G is the grate. M is the down run ofi-take with shutofi' valve N.O is the up run off-take with shut-01f valve at P. Q is one off-take forblast gases as well as the inlet for air blast. R is a double valvecontrolling the course of the gas through either cit-take O or Q. Thisvalve R may be provided with a common valve stem with parts so arrangedthat it will close passage through one off-take while permitting passagethrough the other, and vice versa, and in the present construction thepassage through S is open when the stem is in its up position and isclosed when the stem is in its lowest or down position. S is an annularcollecting chamber for the gases passing through flues U and out at Q. Sis also the heatin chamber for air blasted through valve F and inlet Q.T is an annular recess formed by a sharp deflection in the generatorwall. The inlet for tar or oil is shown at C. More than one tar inlet isemployed, but for simplicity and clearness only one tar inlet is shown.W is the connecting pipe for gas from a down run,or down blast with themain outlet X. W is a dust chamber and Z is a contraction in the lowerportion of the generator wall.

It will be noted that the generator comprises generally a vertical shafthaving suposed frusto-conical sections, separated y the annular recess Twhich is o n to the fuel bed. A plurality of paralle air inlet passagesor flues U are formed in the wall of the shaft, these passages beingsubstantially upright and communicating with the annular recess T forthe admission of air to the fuel bed. Likewise steam and carburettingmaterial are admitted adjacent the air admission ports.

This combination generator may be operated in several different ways, asfollows:

(1) When using bituminous coal and generatin water gas by anintermittent process, I prefer to operate as follows; the ignited fuelis heated to incandescence by air blasting through inlet D. The valves Nand F are closed and R is raised so that the blast gases pass outthrough flues U and off-take Q and out at X. After the fuel in the lowerzone is incandescent and before reaction CO +C=2CO can take place to anyappreciable extent, the blast at D is shut off and valve F is raised andvalve R lowered. The air blast through F is started and air which ispreheated by the time it strikes the fuel passes through Q, S and U tothe fuel. The fuel in a higher zone of the generator is thus heated andthe blast gases pass up through the upper zone of the fuel bed, outthrough offtake 0, through P, and out at X. When the fuel issufliciently hot, air blast is turned off at F, and steam is admittedthrough G by opening valve I. The steam passes up through the full depthof the fuel bed and out through 0, P and X to the holder. After a shortinterval when the fuel is no longer hot enough to generate good bluewater gas, the c cle is repeatedonly steam is admitted at H and a downrun made. In this case valve N is open and P closed and R is lowered,permitting the gas to pass out through M, N, W and X. It is to be notedthat the time of contact of the steam and incandescent fuel isconsiderably greater than the time of contact of the blast gas and thefuel. Thus during blastin more complete combustion of carbon ta es placeand reaction (I)-C+O =CO predominates over reaction (II)CO,+C=2COandmore heat is liberated in the generator. Durin the steam run, the timeof contact is so long t at the reactionH O-l-C=CO+H takes place morecompletely and there is less of reaction- C+2H,O=CO,+2H,.

(2) When using bituminous coal and making carburetted water gas, Iproceed similarly as in the method described above only during the steamrun I admit tar 01; oil through tar inlet C entering in the recess T ofthe generator. On down runs I prefer to admit the tar during the latterpart of the run only, thus preventing the complete cracking of thehydrocarbons into hydrogen. During up runs, I prefer to admit the tar oroil during the first part of the run or during the entire run.

(3) When makin tinuous process, I

producer gas by a conlow air into the fuel through D and simultaneouslyblow steam into the fuel at H, meanwhile having valves N and F closed, Popen and R down so that glgie gases generated pass out through 0 andentering at D, open valve F and blow air in through Q, S and U, andsimultaneously I shut off steam entering at H and force it through G byoperating valve I. This alternate changing keeps the fire in moreuniform condition and eliminates blow holes and the tendency for them toform. I attain, in this manner, a more uniform temperature throughoutthe fuel bed and can therefore operate between smaller maximum andminimum temperature limits and can thus avoid the clinker difficultieswhich commonly pre- Vail when using coals with a low ash fusing point.

(4) When making carburetted producer gas I operate similarly as in (3),only I blow tar or oil into the fuel bed through the tar ports C duringa part of, or the complete, time of operation. I prefer to make somedown blasts, also, which help to give a more perfect control over thetemperature, clinker, and the cracking of the tar or oil. When the downblasts are made the air at D is turned off and air is forced in throughF, Q, S and the fiues U. Steam is admitted through H and valve N isopen, P is closed and R is down. Obviously any desired carburettingmaterial may be used. For example, powdered coal or other pulverizedcarbonaceous material may be blown into the fuel bed through the ports0.

(5) When making water gas using coke or anthracite coal as fuel, Ifrequently blast up from D through the entire bed of fuel taking theblast gases out at 0, through P and X.

Thisis sometimes necessary when an increased" amount of CO orcombustible is desired in the blast gas (as when checker chambers are tobe heated). This is accomplished by clos ing valve N and F, opening P,lowering valve R and starting blast through D. Using this kind of fuelit is sometimes necessary to blow steam in from the top of the fuel bedin order to keep the top of generator from becoming too hot. This can bedone and to good advantage by opening valve V permitting steam to entergenerator at E. The gas produced may be taken off through M and N, atbottom of generator, or through U, S, Q, and X by merely operating thevalves. When operating the latter way, air or steam may be blown in(beneath the grate) through D and G respectively, while the steam isentering at E.

(6) \Vhen operating with a strong coking coal I prefer to operate inanother different manner. I make the usual u blast through D and thesubsequent blast through F, Q, S and U up through the fuel bed and thenmake the up run as in (1) by admitting steam at G, taking off the gasthrough 0, P and X, but with this difference I admit a small quantityAfter a given interval I shut off the ail.

l I m of air through F, Q, S and U during the up runs. Not enough air isadmitted to cause combustion to continue but enough to cause oxidationor incipient combustion in the coking coal. The oxidation I finddecreases the tendency for the coal to cake and mat together bypartially destroying its strong coking tendencies. I find this to beparticularly advantageous when making carburetted gas. The tar or oilalong with the blue gas reaction cool the fuel to such an extent thatthe oxygen in the air thus admitted reaches the fuel at a higher levelthan otherwise. Further, I prefer to admit this air during the latterpart of the run.

My generator is so designed and equipped that when desired the fuel canbe blasted with hot air from the flues U, either up or down or both waysat once by merely operating the valves. The amount of such blast goingeither up or down can be controlled by the valves N and P of Fig. 1.When blasting both up and down at the same time I operate as follows: Iopen air blast valve F, and take-off valves N and P and lower valve R.The steam run can now be made either upshown so as to prevent the coalfrom caking and sticking on coking, and causing it to pass down throughthe generator due to its own weight, as fast as the fuel is consumed.

(3) Only a very small amount of free space exists above the fuel bed inthe generator.

(4) Down run steam ports are below the coking zone. Thus coking is notretarded by down run steam as it is in common practice when bituminousfuel is used.

(5 An off-take for the blast gas is provide below the coking line, Fig.1U and S, whereby a greater proportion of the volatile matter of thecoal is utilized in the blue gas.

(6) A means of blasting the fuel with preheated air is provided throughS and U- Fig. 1, whereby the fuel can be blasted with air at pointsconsiderably above what is usually known as the hot zone. By avoidingthe necessity of passing this air through the lower hot zone, I amenabled to produce complete combustion in the middle of the fuel bed. Incommon practice duringthe latter part of the blast there is very littlecomplete combustion, or rather the CO formed combines with carbon (C-i-CO,=2UO) and absorbs heat, simultaneously producing considerable CO inthe blast gas.

(7) A means is provided for carburetting the gas by injecting tar or oilinto the fuel bed at especially devised entry ports. Under the portionof the wall sloping away from the fuel in which is formed the recess T.

(8) A portion of the generator wall, where air, steam and tar isadmitted, is sloped at such an angle that the fuel will not be in permanent contact with it, thus creating an annular space T that will allowthe steam, tar and air an opportunity to pass through the fuel bedevenly. Clinker can not form and stay on this wall for obvious reasons.

(9) There is a constriction in the size of the generator at and slightlyabove the clinker zone. This causes an increased velocity of the gases,and, during blasting, the ash has a better opportunity to fuse and runfree from the wall. This prevents the arching of clinker in umbrellaformation a foot or-two above the grates, which is a common source oftrouble in present practice.

(10) A means is provided for making producer gas with less poking of thefire, more uniformity of temperature in the fuel bed, and less troublefrom blow holes. This is provided by the triple steam connections E, Hand G, and the double air connections D and Q.

(11) A combination method of blasting is afforded in that the generatorcan be blasted either way from the middle, or both ways, up and down,from the middle, with hot air.

(12) A combination method of making steam runs is afforded in that steamcan not be only blown in from top or bottom, but it can be blown in fromthe middle of the fuel bed either up or down, or both up and downsimultaneously. Further, when steam is admitted at either top or bottomof fuel bed the gas produced can be taken off either at the opposite endof generator or at about the middle as through flues U in Fig. 1.

When blasting through D and taking the blast gas off through U it isevident that there can not be any smoke produced for the fuel isentirely carbonized between the grates and U. When blasting through F, Qand U the air being preheated permits the blast gas which now passesthrough 0, P and X to leave at a temperature above the ignition point ofthe combustible constituents which can be burned to complete combustionby the addition of secondary air as in an auxiliary carburettor or whencoming in contact with air at the stack.

The steam is more completely decomposed with the formation of less CO,when using my generator due to the maintenance of a hot zone higher upin the generator than in common practice. I am able to increase thecapacity of a given size set for the same reason which is due to thefact that for a given amount of air blast I get more heat liberated inthe generator since I have less CO formed and more C0 The fuel in theash is minimized due to better temperature control, to the fact that nouncarbonized fuel ever reaches the grate, and chiefly on account of theemployment of the upper air blast through F, Q, S and U.

I recognize that the composition of fuels in difl'grent parts of thecountry varies, that the ash fusibility is not the same, and therefore Ido not specify a given slopefrom the narrow zone Z to the grates nor thedistance of this Zone above the grates.

I claim:

1. A combined water gas generator and gas producer comprising asubstantially upright, lined shell for retaining a bed of ignited solidfuel, said shell having an annular recess in said lining intermediatethe ends of said shell and contacting said fuel, said shell beingprovided with separate and independent passages for admitting steam andan air blast directly to the fuel bed at said annular recess, outletsadjacent the top and bottom of said shell for the discharge of gas andvalves for controlling said discharge out lets.

2. In a generator for the manufacture of water gas, a container forsolid fuel comprising a single upright shell provided with a V-shapedannular recess in its inner wall between the ends of the fuel bed, meansfor admittin steam and a preheated air blast to the fuel ed at saidannular recess, and for discharging finished as therefrom.

3. In a generator or the manufacture of carburetted water gas, acontainer for solid fuel comprising a sin 1e upright shell having aninner lining, sai generator being con structed to provide an annularrecess formed in said inner lining between the ends of the fuel bed, andprovided with separate and independent means for admitting steam,carburetting material and an air blast respectively to the fuel bed atsaid annular recess and having ports for the discharge of the finishedgas, said air blast passing through one of said ports in a directionreverse to that of the gas discharged therethrough, and means forcontrolling the discharge of said gas through said ports.

4. A carburetted Water gas generator comrising a-vertical lined shellfor retaining a lied ofignited solid fuel, and having a recess in saidlining contacting said fuel and located midway of the ends of the fuelbed, said shell being provided with a passage opening into said recessfor the admission of steam,

means independent of said steam passage for admitting an air blast tothe fuel bed at said annular recess and for preheating said air blastwithin the shell lining before its discharge into said annular recess,passages, sep

arate and independent of said air and steam passages, for admittingcarburetting material to the fuel bed at said annular recess, said shellhaving outlets at top and bottom for the discharge of gas, and valvesfor controlling each of said gas outlets.

5. In a generator for the manufacture of combustible gas, a containerfor solid fuel comprising a single upright shell constructed with anintake port for the admission of a blast adjacent the bottom, and withan inner wall intermediate the ends flared downwardly for a distance andarranged to cooperate with the contained fuel and to provide an annularrecess, said shell having ports at said recess for the admission of airblasts or discharge of gas and provided with means for discharging steamin said recess, means for admitting steam at the bottom and top of saidshell, said shell rovided with ports for discharging the finis ed gas atthe top and bottom, and means for controlling the admission of blast andsteam in a predetermined manner, and means for controlling the dischargeof the finished gas from either end or from the ports at said annularrecess, whereby the gas may be discharged and the contained fuel may beblasted in either direction, or a plurality of direct-ions'as desired.

6. n a combustible gas generator, a container for solid fuel comprisinga single upright shell constructed with an intake ort for the admissionof a blast adjacent the ottom and with an inner wall intermediate theends flared downwardly for a distance and arranged to cooperate with thecontained fuel, and to provide an annular recess, said shell havingports at said space for the admission of air blasts or discharge of gas,and provided with means for discharging steam in said space and withmeans for discharging a carburetting material in said recess, meansforadmitting steam at the bottom and top of the shell, said shell beingprovided with ports for discharging the finished gas at the top andbottom, and means for controlling the admission of gas and steam in apredetermined manner, and means for controlling the discharge of thefinished gas from either end or the ports at said annular recess,whereby the gas may be discharged and the contained fuel may be blastedin either direction or a plurality of directions as desired.

CLAUDE WINFIELI) BOTSFL SJ- Ill

